MTL 200 LAB 4 LEAD-TIN PHASE DIAGRAM
PRACTICE EXAMINATION 2026
QUESTIONS WITH ANSWERS GRADED A+
◍ Influencing factors of quench test.
Answer: -Alloys-quenching material (water best, oil, air worst)-velocity,
temperature of quenching material-size of solid-thermal conductivity
◍ Solid Solution.
Answer: forms when as the solute atoms are added to the host material the
crystal structure is maintained and no new structures form
◍ EMF series.
Answer: Just need to know the name?
◍ Binary Phase Diagram.
Answer: has two components; usually one main variable - temperature
◍ Martinsite formation.
Answer: cooled rapidly (~5 seconds)90% M + 10% γ
◍ Large ΔT.
Answer: -Large number of nuclei-Slow growth-Small grain size
◍ Composition & Primary Phases of Eutectic Systems.
Answer: - hypoeutectic: less than C(e); α primary phase- eutectic: = C(e); α
+ β primary phase - hypereutectic: greater than C(e); β primary phase
◍ Soluble Material.
Answer: solid solution at all proportions as solid
◍ Alloy.
Answer: metal in which impurity atoms have been added to impart specific
characteristics
, ◍ Carbon iron cooling C<0.76 wt% carbon.
Answer: γ -cools-> α + γ (above T(eutectoid)- γ in grain- α thick G.B.Cools
Below TE-α ferrite background(pearlite ferrite)-Fe3C lines in grain-α ferrite
thick G.B. (protectoid ferrite)
◍ Liquidus vs Solidus.
Answer: - liquidus: separates liquid phase from Solid + Liquid Phase field -
solidus: separates solid phase from Solid + Liquid Phase field
◍ Continuous cooling.
Answer: -If steel never touches nose then pure martensite-If steel touches
nose then P + M-If steel goes through nose then pure pearlite
◍ Phase composition.
Answer: Chemically, using tie line
◍ Solubility Limit Definition.
Answer: max concentration of solute atoms that can dissolve in a solvent to
form a solid solution
◍ 2 Phases: Liquid and α.
Answer: L (liquid) α (FCC Solid Solution)
◍ Eutactoid reaction.
Answer: γ -(cooling)-> α + βheat to reverse(one solid cools to two other
solids)
◍ Solvent.
Answer: element or compound that is present in the greatest amount
◍ Solute.
Answer: element or compound present in minor concentration
◍ Phase diagram.
Answer: Used to design and control heat treatment procedure
◍ AISI or SAE.
Answer: AB XX-A chemistry-B weight of alloy A-XX weight of carbon (60
PRACTICE EXAMINATION 2026
QUESTIONS WITH ANSWERS GRADED A+
◍ Influencing factors of quench test.
Answer: -Alloys-quenching material (water best, oil, air worst)-velocity,
temperature of quenching material-size of solid-thermal conductivity
◍ Solid Solution.
Answer: forms when as the solute atoms are added to the host material the
crystal structure is maintained and no new structures form
◍ EMF series.
Answer: Just need to know the name?
◍ Binary Phase Diagram.
Answer: has two components; usually one main variable - temperature
◍ Martinsite formation.
Answer: cooled rapidly (~5 seconds)90% M + 10% γ
◍ Large ΔT.
Answer: -Large number of nuclei-Slow growth-Small grain size
◍ Composition & Primary Phases of Eutectic Systems.
Answer: - hypoeutectic: less than C(e); α primary phase- eutectic: = C(e); α
+ β primary phase - hypereutectic: greater than C(e); β primary phase
◍ Soluble Material.
Answer: solid solution at all proportions as solid
◍ Alloy.
Answer: metal in which impurity atoms have been added to impart specific
characteristics
, ◍ Carbon iron cooling C<0.76 wt% carbon.
Answer: γ -cools-> α + γ (above T(eutectoid)- γ in grain- α thick G.B.Cools
Below TE-α ferrite background(pearlite ferrite)-Fe3C lines in grain-α ferrite
thick G.B. (protectoid ferrite)
◍ Liquidus vs Solidus.
Answer: - liquidus: separates liquid phase from Solid + Liquid Phase field -
solidus: separates solid phase from Solid + Liquid Phase field
◍ Continuous cooling.
Answer: -If steel never touches nose then pure martensite-If steel touches
nose then P + M-If steel goes through nose then pure pearlite
◍ Phase composition.
Answer: Chemically, using tie line
◍ Solubility Limit Definition.
Answer: max concentration of solute atoms that can dissolve in a solvent to
form a solid solution
◍ 2 Phases: Liquid and α.
Answer: L (liquid) α (FCC Solid Solution)
◍ Eutactoid reaction.
Answer: γ -(cooling)-> α + βheat to reverse(one solid cools to two other
solids)
◍ Solvent.
Answer: element or compound that is present in the greatest amount
◍ Solute.
Answer: element or compound present in minor concentration
◍ Phase diagram.
Answer: Used to design and control heat treatment procedure
◍ AISI or SAE.
Answer: AB XX-A chemistry-B weight of alloy A-XX weight of carbon (60
